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DCC or Microcontroller

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  • Member since
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  • 42 posts
DCC or Microcontroller
Posted by gbcutter on Wednesday, March 11, 2009 5:58 PM

 I am more interested in building scenery than in running trains. (I hope that doesn't shock or offend anyone) I would like to have 2 trains running automatically at the same time without having to run around throwing switches. I was considering using a Microcontroller or PIC controller with a DC system. I am planning a 2-line out-and-back layout with a reversing loop at both ends. I could build a controller to do this, but it might be simpler with DCC. Can I program a DCC system to throw turnouts and run 2 trains at the same time? I would like to have one train running out while the other is heading back, continuously. Cost is not a major consideration.

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Posted by Phoebe Vet on Wednesday, March 11, 2009 7:39 PM

I'm confused.  If you have two trains running on a two line out and back, why do you need reverse loops at the ends?  Why not just go out on track one and back on track two?  If the two lines are independent, then you will need TWO reverse loops on each end.

Dave

Lackawanna Route of the Phoebe Snow

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Posted by jrbernier on Wednesday, March 11, 2009 7:41 PM

  An 'out of the box' DCC system is not going to provide the automatic program control you are describing.  Either DC or DCC systems can be adapted to do what you describe.  You will need several items:

  • Detection - you need to sense direction and where the train is on the layout & how your switches are aligned.
  • Control Logic - This will 'read' the detection and make decision on throwing switches/stopping or starting the trains and what direction they should be going.

  All of this may need a computer with more that a simple PIC processor.  Check out the JRMI web site for DCC ideas:   http://jmri.sourceforge.net/

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by Paul3 on Wednesday, March 11, 2009 7:56 PM

There are multiple ways to do this with DCC, but it depends quite a bit on what you have and what you want.

If these two trains are on isolated sections of track (IOW, it's impossible to have the trains hit each other), then it's quite simple.  If you got Tortoise machines with the Hare controller from Tony's, the switches throw automatically based on a small detection section in the Hare.  So if you had a typical reverser section (a single track main with a balloon track), the train goes into the loop, then hits the detector (and the autoreverser for track power).  The Tortoise throws before the train gets back to the switch, and the train rolls through.

The two trains would just run continuously with or without a throttle, provided the command station is set up that way.

Now, if you have two trains on the same track, then life gets interesting.  Either you need to make sure your two trains run at exactly the same speed, or you need to start adding detection and signalling (which gets real expensive really fast).  It's a little easier with DCC because of BEMF decoders (sort of like cruise control for locos) so you don't have to worry about speeding up or slowing down for grades and curves, but if you want the trains to stop at stations or speed up on straightaways, then you'll need a PC throttle that can interface with all that and control the trains directly. 

Paul A. Cutler III
*******************
Weather Or No Go New Haven
*******************

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Posted by Vail and Southwestern RR on Wednesday, March 11, 2009 10:45 PM

If I was wanting what it sounds like you want, I would be tempted to lay down two completely independent loops, design things so that it isn't obvious that's what you have (maybe even including switches between them that you'll never use), and just run two DC throttle, and let it go at that.  Of course, if you ever wish you had done differently.....

Jeff But it's a dry heat!

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Posted by ATLANTIC CENTRAL on Wednesday, March 11, 2009 10:57 PM

gbcutter,

If that is truely all you want to do, you should talk to Chuck at www.oaktreesystems.com , he does that kind of thing all the time for commercial display layouts. He supplied the control system for the new HO layout just built at the B&O Railroad Museum in Baltimore.

He is well versed in using stand alone processors for that sort of thing. And he has a line of hardware that will interface with the proccessor to run the trains.

Sheldon

    

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Posted by challenger3980 on Wednesday, March 11, 2009 11:22 PM

    Are you set on doing this in HO or N scale? If You  were willing to consider 3 Rail O-Gauge, using locomotives equipped with command  control (Lionel TMCC, Legacy or MTH's DCS) You can add an ARC (Action Recording Controler) An ARC will allow you to set your ARC run  a sequence, which can include starts, stops(such as at a  station) coupling/uncoupling speed &direction  changes etc. The  ARC will record any function that your trains will do, and then repeat it whenever you wannt it to. This is easy and sounds like it is well suited to what you want to do. The scenery on a Hi-Rail O-Gauge layout can be built to the same standards as any other scale, but being 1:48 scale, rather than 1:87 or 1:160 can be easier to work with.

  They're NOT your Grandpa's Lionels anymore,

Doug 

May your flanges always stay BETWEEN the rails

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Posted by jasperofzeal on Thursday, March 12, 2009 6:06 AM

gbcutter,

Model Railroader (Dec 2006, pg.94) had an article titled: "Turning trains hands-free with DCC".  It states:  "Make an automated reverse loop for Digital Command Control layouts using off-the-shelf components".  The article listed all the needed items such as: detectors, reversing unit, switch motor, etc.  Hooking up all the components looks pretty easy and the way it works seems pretty simple.  This automated reverse loop is for a DCC layout, so at the very least, a low end DCC system will be needed.  If you have MR back issues, look it up, it may be what you're looking for. 

TONY

"If we never take the time, how can we ever have the time." - Merovingian (Matrix Reloaded)

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Posted by gbcutter on Thursday, March 12, 2009 1:24 PM

Thanks for all the good ideas. Using a straight DCC system may be the easiest way to go, but it looks like the full control system at oaktreesystems.com might allow for the more  complicated running which I hope to have. Even the idea of 2 independent DC or DCC lines might work.

I'm modeling in n-scale. Since I am not interested in 'operations' my current system is all manual DC control.

The double line is planned for an out-bound line and an in-bound line.  There will be one reversing loop for both trains at one end and two reversing loops overlapping at the other end. At the double end, I plan to have the freight line reverse clockwise on one loop and the passenger line to reverse counter-clockwise on the other loop.

I know it sounds complicated, but that's half the fun for me.

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Posted by AlienKing on Thursday, March 12, 2009 2:11 PM
        ______
       /      \
      /        \
     /          \
    |            |
    |            |
    |            |
    |            |
     \          /
      \        /
      A\      /B
       |\    /|
       | \  / |
       |  \/  |
       |  /\  |
       | /  \ |
      C|/    \|D
       |      |
       |      |
       |      |
       |      |

You could control the turnouts mechanically using springs.

Turnouts C and B should be pulled towards the left. Turnouts A and D should be pulled towards the right. This will make the train on the left track always come back to the left track and the train on the right track always come back to the right track. The springs should be loose enough that they don't cause trains running against the points to derail. You also need to use turnouts with insulated(plastic would work best) frogs in this approach. One auto-reverser and you should be good to go, as long as your trains don't collide.

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Posted by CSX Robert on Sunday, March 15, 2009 2:02 AM
There are, of course, several ways to approach layout automation.  As has already been mentioned, Oak Tree Systems and JMRI are a couple of options.  Here are some more items you should look at:


Although automation usually uses some form of detection, there are sometimes ways around it, depending on the routes you want automated.  If you do need detection, it can be done with current detectors, infrared detectors, or magnetic reed switches.

 

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Posted by steamrailroader on Sunday, March 15, 2009 2:14 AM

 This is also somthing that would be easy to do with a C/MRI system

by JLC Enterprises 

 

Bruce wrote the book on how to do this years ago. He is still expanding the system. He is always happy to answer the phone and talk about what you wish to do.

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Posted by modelmaker51 on Sunday, March 15, 2009 5:48 AM

http://www.dallee.com/ Has been doing just what you described for both home and display layouts.

Jay 

C-415 Build: https://imageshack.com/a/tShC/1 

Other builds: https://imageshack.com/my/albums 

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